The present invention relates generally to a brushroll for a vacuum cleaner sweeper, and more specifically, the invention is directed to a brushroll having angled tuft patterns which increase the performance of the brushroll.
Conventional vacuum cleaner sweepers typically include some type of brushroll for increasing cleanability. Prior art brushrolls generally comprise a wooden spindle that carries a plurality of tufts. A tuft consists of a plurality of thin predominantly nylon bristles. Most brushrolls contain one or more patterns of tufts that typically protrude from the spindle, perpendicular to the spindle longitudinal axis. The patterns conventionally form rows of tufts. The brushroll is typically turned by a pulley and belt system that is directly or indirectly attached to a vacuum cleaner motor. In the known operation of a vacuum sweeper, the user pushes the vacuum as the brushroll generally spins at a speeds in excess of 5,000 rpm. As the brushroll is rotated by the pulley, the tufts contact the carpet fibers to agitate the fibers, loosening dirt particles resting on or between the fibers. In practice, dirt particles loosened by the brushroll are then more effectively removed from the carpet by the suction forces of the vacuum.
It is known in the prior art to angle tufts near either end of the spindle xe2x80x9cto reach outxe2x80x9d to carpet areas near the edge of the vacuum sweeper housing. Tufts of this design can be found in the prior art, for example, in U.S. Pat. No. 6,003,198 to Stegens and U.S. Pat. No. 5,373,603 to Stegens. These designs feature a limited number of non-perpendicular tufts near either end of the spindle that angle toward the spindle end. In addition to increasing the effective coverage area of the sweeper, the angled tufts tend to prevent threads and other materials from embedding in the bearing end cap.
Other prior art spindle designs use angled tufts. U.S. Pat. No. 4,307,479 to Mertes et al. discloses a brushroll having an angled tuft pattern, with tufts perpendicular to the spindle longitudinal axis at or near the center of the spindle, and other tufts increasingly angled toward the nearest spindle end as a function of their distance from the spindle midpoint. Each row of tufts is angled similarly in these designs.
It is well accepted in the art that the cleanability of a vacuum sweeper may be measured by ASTM test procedure F608-89. Various parameters of a brushroll can be altered to increase the cleanability of the vacuum. Tuft material of increased strength, thickness, or length may be employed. The overall diameter of a tuft may also be increased. However, these methods can lead to decreased maneuverability for the vacuum and make the vacuum difficult to push. Also, due to the increased force required to rotate the brushroll to overcome increased frictional forces between the brushroll and the carpet, accelerated and premature belt wear may occur. Manufacturers may solve the problem of decreased maneuverability by producing self-propelled or partially-propelled models. Adding these or similar options increases the cost of the vacuum cleaner.
There remains a need in the art for an improved brushroll assembly that can significantly increase the cleanability of a vacuum sweeper, with little or no increased cost.
The present invention is directed to an improved brushroll for a vacuum cleaner sweeper. The brushroll features angled tuft patterns that increase the performance of the brushroll, without increasing cost or changing other brushroll or vacuum characteristics.
The effect of this angled pattern is to increase agitation of the carpet fibers. Tufts with a common sweeping path form a tuft set. One tuft of a tuft set applies forces on the carpet fiber in two directions, a direction parallel to the movement of the cleaner and a direction perpendicular. An opposing tuft in the same tuft set, applies forces in the parallel direction, and in an opposing perpendicular direction, 180xc2x0 from the first perpendicular direction. The advantageous effect, that is documented through experimentation, is increased cleanability performance for the vacuum, compared to prior art brushroll designs.
According to one embodiment, a brushroll for use in a vacuum cleaner comprises a spindle and first and second rows of rotationally opposed bristles tufts. The first row has a majority of its tufts disposed at acute angles with respect to the spindle axis and tilted toward one end of the spindle. The second row has a majority of its tufts disposed at obtuse angles with respect to the spindle axis and tilted toward the other end of the spindle. xe2x80x9cAcutexe2x80x9d and xe2x80x9cobtusexe2x80x9d as used herein refer to angles having one of their legs parallel to the spindle axis and extending toward a common end of the spindle.
The tilted tufts of the first row may be paired with tilted tufts of the second row with the tufts in each pair being equidistant from an end of the spindle, so that the tufts of each pair have a common sweeping path. The first and second rows may be diametrically opposed with respect to the spindle. A majority of tilted tufts of the first row may be at an obtuse angle of 97xc2x0, with at least some of the tilted tufts of the second row at supplemental angles of 83xc2x0.
According to another embodiment, a vacuum cleaner brushroll comprises a spindle and fist and second rows of bristle tufts extending along helical paths. The first row begins near one end of the spindle and continues toward the other end. The first row has a group of tufts perpendicular to the spindle axis, a second group of tufts tilted toward the other end at an angle of 3xc2x0 from the perpendicular to the spindle axis, a third group of tufts tilted toward the other end at an angle of 5xc2x0 from the perpendicular to the spindle axis, and a fourth group of tufts tilted toward the other end at an angle of 7xc2x0 from the perpendicular to the spindle axis.
The second row begins near the other end and continues toward the one end. The second row has a first group of tufts perpendicular to the spindle axis, a second group of tufts tilted toward the one end at an angle of 3xc2x0 from the perpendicular to the spindle axis, a third group of tufts tilted toward the one end at an angle of 5xc2x0 from the perpendicular to the spindle axis, and a fourth group of tufts tilted toward the one end at an angle of 7xc2x0 from the perpendicular to the spindle axis.
The fourth group of tufts of the first row is rotationally opposed to the first, second, third and part of fourth group tufts of the second row. The fourth group of tufts of the second row is rotationally opposed to first, second, third and part of the fourth groups of tufts of first row.
The first and second rows of tufts may be diametrically opposed.
According to another embodiment, a vacuum cleaner brushroll comprises a spindle and first and second rows of rotationally opposed bristle tufts. The first row has tufts arranged in tuft groups that are tilted toward one end of the spindle. Tufts in each group in the first row are tilted at the same angle with respect to the perpendicular to the axis of the spindle.
The second row has tufts arranged in tuft groups that are tilted toward the other end of the spindle. Tufts in each group in the second row are tilted at the same angle with respect to the perpendicular to the axis of the spindle.
Each row may include at least one group of tufts that are perpendicular to the axis of the spindle. The tuft groups in the first row may be tilted at increasingly larger angles progressing toward one end of the spindle. The tuft groups in the second row may be tilted at increasingly larger angles progressing toward the other end of the spindle. The first and second rows of tufts may be diametrically opposed with respect to the spindle.
According to yet another embodiment, a brushroll assembly for use in a vacuum cleaner comprises a generally cylindrical shaped spindle having a first end, a second end and a longitudinal axis. A plurality of tufts are arranged in at least two tuft patterns, wherein each of the tuft patterns extends along the longitudinal axis. The tuft patterns define a plurality of tuft sets.
Each tuft set includes one tuft from each of the at least two tuft patterns, wherein each tuft in the set is equidistant from the first end. At least one tuft set has at least one tuft disposed at an acute angle with respect to the longitudinal axis, and at least one tuft disposed at an obtuse angle with respect to the longitudinal axis.
A majority of the tuft sets may have at least one tuft disposed at an acute angle with respect to the longitudinal axis and at least one tuft disposed at an obtuse angle with respect to the longitudinal axis. The tuft patterns may be generally helical-shaped rows. The tuft patterns may be equally spaced with respect to each other around the circumference of the spindle.
The tufts may be disposed at acute angle ranges from 70xc2x0 to 90xc2x0 and obtuse angle ranges from 90xc2x0 to 110xc2x0 with respect to the spindle longitudinal axis. The acute angle and the obtuse angle may be supplementary angles.
In yet another embodiment, a brushroll assembly for use in a vacuum cleaner comprises a generally cylindrical shaped spindle substantially circular in cross-section throughout its entire length. The spindle comprises a first end, a second end, and a longitudinal axis.
A plurality of tufts are arranged in two generally helical-shaped rows. Each of the rows extends along the longitudinal axis between the first end and the second end. The tufts comprise a plurality of tuft pairs. Each pair includes one tuft from each of the tuft rows. Each tuft in the pair is equidistant from the first end. The tufts in each pair are diametrically opposed with respect to the spindle.
A majority of tuft pairs comprise one tuft disposed at an acute angle with respect to the longitudinal axis and one tuft disposed at an obtuse angle with respect to the longitudinal axis. The acute angles range from 70xc2x0 to 90xc2x0 and the obtuse angles range from 90xc2x0 to 110xc2x0 with respect to the longitudinal axis.